Question

I have a table named attribute:

id attributeid type
1         8      2
2         8      1
3         4      1

So how can I select attributeid that have both types of 2 and 1. In this case, only attribute 8 is qualified that.

select attributeid 
from attribute
where type in (1,2)

This doesn’t produce the results I want, as it returns 4,8 which is wrong.

Thanks.

Answer 1

You can use something like this:

select t1.attributeid
from yourtable t1
where type = 1 
  and exists (select type
              from yourtable t2
              where t1.attributeid = t2.attributeid
                and t2.type = 2)

See SQL Fiddle with demo